In the past, as this type of light-emitting devices, there has been proposed, for example, a light-emitting device 101 having a structure shown in FIG. 11 (see document 1 [JP 2013-93635 A]).
The light-emitting device 101 includes a low temperature co-fired ceramics (LTCC) substrate 110, a silver reflection layer 103 formed on the LTCC substrate 110, a glass layer 104 to cover the silver reflection layer 103, and an LED chip 102 located on the glass layer 104. Further, the LED chip 102 and bonding wires 107 are encapsulated by a dome-shaped phosphor-containing encapsulating resin 108. The LTCC substrate 110 is constituted by a plurality of (ten) LTCC layers 110a to 110j. In the light-emitting device 101, the LTCC substrate 110 has a thickness of 1 mm, the silver reflection layer 103 has a thickness of 0.25 mm and the glass layer 104 has a thickness of 0.01 mm.
It is considered that light-outcoupling efficiency of the light-emitting device 101 is likely to decrease due to some causes such as absorption by the LED chip 102 and multiple reflection in the LED chip 102 regarding light emitted from the LED chip 102 and reflected by the silver reflection layer 103.